Question

1. how can astronomers tell where new star formation is happening in interacting galaxies? (with four multiple - choice options, some text in options is unclear due to image quality)

Explanation:

New star formation produces hot, bright blue stars (and star clusters) that emit strong ultraviolet light. Astronomers detect this UV light to identify active star-forming regions. Dark dust lanes obscure light but don't indicate formation; other options don't target the signature of new stars.

Answer:

By using ultraviolet light